IC405 flames between the rain

[Snoani]

Good evening all

The weather on the Isle of Wight has been pretty rubbish lately, with so much rain and flooding.  Clear skies have been rare and when they have arrived, there has been rolling cloud and a risk of showers.  My rig actually was rained upon last week unexpectedly, which has made me a bit nervous with the weather as it is.  I have however managed to capture a little data during this period and so I present a quick Flaming Star Nebula.  

This was captured with a William Optics GT81IV, ZWO ASI 1600MM and Antlia LRGB-V Pro & 3nm HA filters.  Once I stripped out cloud impacted frames it is made up from 3.5h of Lum, 1h of each RGB (binned 2x2) and 3h of Ha, processed in Pixinsight. 

This is the third time that I have attempted to capture this target and the first two times I really struggled to draw out the nebula while containing the stars but on this occasion it seemed to happen naturally.  If I am being honest I think I have overcontrolled the larger stars on the left somewhat.  

I looks like the rest of this new moon period will continue to be a wash out so I hope t be posting again after the next period with some Orion related activity.  

Thanks for looking.  

[whipdry]

Really like the one, a good example of perseverance.

Peter 

[Rodd]

Very nice--How did you avoid microlensing artifacts around the bright star?  I use the ASI 1600 and find it to be atrocious with stars.  I am shooting this one now, and the bright star is terrible

[Snoani]

On 18/11/2023 at 13:58, Rodd said:

Very nice--How did you avoid microlensing artifacts around the bright star?  I use the ASI 1600 and find it to be atrocious with stars.  I am shooting this one now, and the bright star is terrible

Thank you very much.  Honestly, microlensing has generally never been a problem for me using this camera.  I've owned this camera for 3 years and the first and only time that I have come across microlensing was earlier this year when I was imaging the ghost nebula in Cassiopeia. Gamma Cassiopeiae came out square in that image but I hadn't experienced it previously or since.

[Rodd]

1 hour ago, Snoani said:

Thank you very much.  Honestly, microlensing has generally never been a problem for me using this camera.  I've owned this camera for 3 years and the first and only time that I have come across microlensing was earlier this year when I was imaging the ghost nebula in Cassiopeia. Gamma Cassiopeiae came out square in that image but I hadn't experienced it previously or since.

I wonder why. I get it all the time. And it sucks

[ollypenrice]

I don't think the stars are over-controlled except in terms of their colour. Of course, most star colour is found around the fainter edges so, when these are reduced, so is the colour. If you could get a bit more colour into them I think you'd be spot on. It's a tricky target to process and I think this is very decent indeed.

Olly

[gorann]

On 18/11/2023 at 14:58, Rodd said:

Very nice--How did you avoid microlensing artifacts around the bright star?  I use the ASI 1600 and find it to be atrocious with stars.  I am shooting this one now, and the bright star is terrible

Yes, I really like it and the blue reflection nebula comes out quite nicely. Regarding microlensing could it be Rodd that you are using longer exposures than @Snoani, whatever he/she uses? Just a guess.

[Rodd]

3 hours ago, gorann said:

Yes, I really like it and the blue reflection nebula comes out quite nicely. Regarding microlensing could it be Rodd that you are using longer exposures than @Snoani, whatever he/she uses? Just a guess.

I don’t think it matters. I experimented with short exposures and while the artifacts were absent in individual subs, they were present in the combined Images. 

[Snoani]

On 19/11/2023 at 18:29, Rodd said:

I wonder why. I get it all the time. And it sucks

 

3 hours ago, Rodd said:

I don’t think it matters. I experimented with short exposures and while the artifacts were absent in individual subs, they were present in the combined Images. 

I am sorry to hear the extent of your problem.  As I have only experienced in once, I haven't delved into it too much. I wonder if it is a problem that really only affects some 1600MM cameras, therefore being a bit of a lottery.  

I have looked closer at the subs for the image that I mentioned above and notice that it was only really occurring in the RGB and not the luminance.  I don't know if this is significant though.  I tend to use the same exposure length for all LRGB filters and as the luminance lets more light through than the colour, maybe I have oversaturated that star somewhat.  

I'm not overly convinced by this suggestion and I think I am clutching at straws.  

[Rodd]

14 minutes ago, Snoani said:

 

I am sorry to hear the extent of your problem.  As I have only experienced in once, I haven't delved into it too much. I wonder if it is a problem that really only affects some 1600MM cameras, therefore being a bit of a lottery.  

I have looked closer at the subs for the image that I mentioned above and notice that it was only really occurring in the RGB and not the luminance.  I don't know if this is significant though.  I tend to use the same exposure length for all LRGB filters and as the luminance lets more light through than the colour, maybe I have oversaturated that star somewhat.  

I'm not overly convinced by this suggestion and I think I am clutching at straws.  

I think your probably right about the sensor.  Not sure about the L vs RGB. It is much more noticeable as focal ratio increases.